Well reaming apparatus



W. R. BARBOUR' WELL REAMING APPARATUS Sept. 28, 194

3 Sheets-S 1 F led Nov. 25, 1944 em 8 W. m5.%m A u n m M W a. T fl W4 MR T a f MYM .J 4 M B Y A L A v. M \\N k.um \A 1 a a A w umH. .w. w wmm wA, S T f. T. 1 3 J w k w Z Sept. 28, 1948.

w. R. BARBOUR WELL REAMING APPARATUS Filed Nov. 25, 1944 If; E- S 3Sheets-Sheet 3 xca l 1:]

Tail 5 Patented Sept. 2a, 1948 WELL ammo arraaa'rus William B. Barbour,Atlanta, Ga.

Application November 2;, 1044, Serial No. 508,121

r 13 Claims.

--Generically this invention relates to reaming devices, but it moreparticularly is directed to a rotary device or apparatus for reaming outto a larger diameter any desired portion of oil wells and the like.Oneof the principal objects of this invention is the. provision of adevice of this character attachable to a string of'drill pipe,controllable from the surface of the ground, and comprising an improvedhollow reamer shaft, and expansible reamer arm construction and shoeassembly associated with said shaft operable to effect reaming out of achamber or enlarging any portion of the well bore and permitting a fluidcirculation through the device including the shoe to the bottom of thewell for clean out purposes and cooling of the reamer arms.

Another object of this invention is the provision of an upper collarstructure having detachable connection with the end of the drill pipeand adapted to be slidably mounted on the upper end of the reamer shaftand to impart rotary motion thereto and to the attached reamer arms andthrust rods. i

A further important object of this invention is the provision of areamer arm assembly adapted to be mounted on streamer shaft, andcomprising a plurality of articulated sets of reamer arms attached atone end to an upper or control collar .and at the other end to a lowerslidable collar and movable into overlying parallelism with the reamershaft and to expanded or reaming position, and means associated with'said collars adapted to transmit-force and. downward movement from theupper to the lower collar and arms when expanded or moving in reamingdirection, said arms being automatically foldable by the upward movementof said upper collar.

Another important object of this invention is the provision of a hollowreamer shaft adapted of a drill pipe and having means adapted to preventits dropping out of or. becoming detached from said collar, a pluralityof sets of e p nsible reamer arms associated with ,said shaft with theirupper ends attached to said collar andtheir lower ends attached to alower slidable collar mounted on said shaft; means in connection withsaid shaft fol-preventing the lower collar from slid-q ing down saidreamer shaft until the reamer arms have substantially reached theirexpanded posit-ion, and means in connection with said shaft to permitthe folding of the reamer arms into-overlying parallelism therewith atany desired point throughout its length.

A further important object of this invention is .th'e'prov-ision of anarticulated reamer arm structure mounted on a reamer shaft and adaptedto v be inserted in a drilled well in folded parallelism with the shaft,and means in connection with said shaft and coacting with said armstructure to initially start the outward movement of said arms inexpanding direction.

A still further important object of this invenand the formation of thefoot structure adapted to prevent movement and sinking of the 'base,

thereby insuring the flow of the circulating fluid through the shoe tothe bottom of the well.

With these and other obiects in view, which will become apparent as thedescription proceeds,

the invention resides in the construction, combination and arrangementof parts, hereinafter .more fully described and claimed, in which like I.to be slidable through a collar attached to the end 7 characters ofreference indicate like parts throughout the severalflgures, of which:Fig. l is a view in elevation with the reamer arms in closed position.

Fig. 2 is an elevation similar to Fig. 1 with the arms in expandedposition.

Fig. 3 is a sectional view with the arms clos and in elevation.

Fig. 4 is a view similar to Fig. 3 with the arms expanded and infragmentary elevation.

Fig. 5 is a fragmentary sectional view showing the ball and cams in armopening position.

Fig. 6 is a fragmentary sectional view showing the lower arm cams in thecam receiving recesses. Fig. '7 is a cross section on the line 1-1 ofFig. 3 showing the cam retaining pins in elevation.

Fig. 8 shows ,the upper collar partly in section, a portion of theconnected drill pipe in section and connected parts in elevation.

Fig. 9 is a similar view to Fig. 8 in elevation with the upper collarpartly in section.

Fig. 10is a fragmentary longitudinal sectional view with the upperreamer arms in elevation.

Fig. 11 is a cross section on the line ll-li of Fig. 10. V

Fig. 12 is'a cross section on the line lI-l! of Fig. 8.

Fig. 13 is a cross section on the line it-iiof Fig. 14 is a longitudinalsection of the shoe structure and portion of the reamer shaft.

Fig. 15 is a cross section On the line ll-ll of Fig. 14.

Fig. 16 is a sectional view of a portion of an oil well showing thereaming device in operative position therein.

Fig. 17 is an elevation of a modified form of reamer arm construction.

The devices of this character with which I am familiar have provendeficient in presenting complex structures, expensive to produce,diflicult to readily position at any desired level, and in other waysunsatisfactory, and it was to overcome such disadvantages by providing aflexible device comprising an upper collar attachable to a string ofdrill pipe adapted to carry and control the articulated reamer arms, andto impart rotary motion to the hollow reamer shaft slidably connectedtherewith, said shaft carrying a fluid and ball controlled cam mechanismadapted to initially start the expanding movement of the reamer arms, aslidable lower collar on said shaft connected to the ends of-the lowerreamer arms, means carried by said shaft coacting with the cam meanscarried by the lower ends of said lower arms to hold the lower collaragainst downward movement until said arms have substantially reachedtheir limit of expansion, and a compound shoe structure adapted to reston the bottom of the well and to support said rotatable shaft andreaming assembly, said shoe including a supporting thrust bearing andaxial bearing surface for said shaft and means for directing the fluidflow from said shaft therethrough to the bottom of the well, that Idesigned the device forming the subject matter of this invention.

In the illustrated embodiment characterizing this invention there isshown a drill pipe I, externally threaded at its lower end as at 2, andan upper collar 3 formed with a threaded countersunk opening 4 adaptedto engage and receive said threaded end of a pipe I. Said collar isprovided in thepresent instance with a vertical opening 5 square incross-section adapted to. fit the hollow square reamer shaft 6 slidablyextending therethrough. It is obvious that the shaft and opening may beof any desired shape adapted to impart the rotary movement of collar 3to said shaft. Threadedly mounted on the upper end of shaft 6 is a nut Iadapted to coact with the shoulder 8 to prevent disengagement of theshaft from said collar as will be well understood. The

upper surfaces of the nut and shaft are concaved as at I to direct aball 9 from the drill pipe i to the hollow bore in of said shaft for apurpose hereinafter more fully explained.

Integrally or otherwise formed on the lower end of collar 3 are theequispaced bifurcated lugs ll positioned over the respective sides ofthe shaft. Adapted for overlying relation with respect to each of thefour surfaces of said reamer shaft 8 are respective sets of reamer armsA comprising upper arm sections i2 hingedly connected at their upperends to lugsl l'by pins l3, and hingedly connected at their lower endsto the upper ends of the lower reamer arms 'or sections H by pins ii,the lower ends of arm sections l4 being connected by pins IE to lugs i1projecting from the upper edge of the slidable ,collar l3, in a mannersimilar to lugs II.

The lower ends of the arm sections l4 are formed with cams l9 adapted toseatin the complemental cam-stop recesses 20 formed in the respectivesurfaces of shaft 3, and which p events downward slidable'movement ofcollar I! (Fig. 3) during lowering of the device in the well D and untilarms l4 have moved to expanded position (Fig. 4). Just below recesses 20and in alignment therewith, said shaft 8 is formed with the recesses 2|,ending at or near the lower end of the shaft and which correspond indepth and width to the recesses 20, and which are adapted to receive thecams l8 and permit closing of the arms A at any point desired when thelower ends of arms i4 are below recesses 20. Each of the respective armsections l2 and I4 is formed at i s forward edge with a cutting edge orcutting teeth i4. The respective reaming arm sections l2 are longer thanthe reaming or cutting sections l4 so that when in open or expandedposition the outer ends of the latter at connections i5 will be elevatedsomewhat with respect to their inner end connections l6 (Figs. 2 and 16)to effect the desired cutting or reaming angle, and distribution of theforces applied to the reaming assembly B during the reaming operation.

Just below the hinged connection ii of the arm sections i2 and i4, andformed in the respective opposed surfaces of shaft 6, are the openings22 terminating in the downwardly extending recesses 23.

Mounted in the openings 22 and with their rounded and beveled edges 22'converging into meeting engagement centrally of the bore i0 (Fig. '1)are the cam members 25 normally seating in the recesses 23 flush withthe surface of said shaft 6. Extending through said shaft 6, spaced fromthe opposed surfaces of the shaft and in parallelism therewith, are thebores 26, and sim'- ilarly extending through the remaining opposedsurfaces and intersecting bores 26 at right angles thereto are thesimilar bores 21. Inserted in bores 26 and through the cams 24 are theshort pins 28 adapted when operatively positioned not to interrupt thebores 21, and inserted in bores 21 and through the remaining cams 24 arethe long pins 29, the ends of which are flush with the opposlte surfacesof shaft 6 (Fig. 3). As clearly shown in Figs. 3 and 7, when the reamerarms l2 and I4 are in closed position the earns 24 are likewise inclosed position within bore ID. If desired, instead of the bores 28 and21, the surfaces of the reamer shaft may be slotted and the cam pins 28and 29 welded or otherwise secured therein.

Sometimes when pressure is applied to arms l2 and I4 by collar 3, byreason of said arms being on dead center at joint H5 or otherwise, theyfail to move in expanding or opening direction, and in order to insurepositive action in such regard the cam '24 arrangement has been providedso that ball 9 (Fig. 5) acting on surfaces 22 under the pressure of thefluid passing through bore I0, is forced between cams 24 elevating camarms 25 and expanding said arms i2 and I4 at Joint l5, thereby startingthe outward and expanding movement of said arms in reaming direction, aswill hereinafter be more fully described.

The bottom surface of .upper collar '3 is formed intermediate adjacentlugs l I and at the four corners of opening 5 or shaft 8 (Fig. 13) withthe threaded openings 30, each adapted to receive the reduced threadedend 3| of a thrust rod 32.

Each of said rods 32 is formed with a shoulder adapted for detachableconnection with a shoe assembly C.

portion and collar 33, depending upon the depth of the well and thelocation of the oil bearin stratum to be reamed with respect to theshoeassembly at the bottom of the well.

In Fig. 1'1 is illustrated a modified form of" reamer arm structure,similar in principle to the form hereinbefore described, but instead ofthe two hinged arm structure A, a three articulated or hinged armstructure A is employed.

This form, while not "limited to, is especially applicable to chambersalready reamed, the pores of the walls of which have become plugged withThe shoe assembly C is adapted, as will directly I more fully appear. torest on the bottom of 1 a well and support the weight of thereamerconstruction, and comprises a complementally formed and threaded collaror socket member 33 adapted to receive the tapered end 31 of shaft 3.Said member 33 is formed .with a bore l0 forming when positioned acontinuation of bore l3 and which extends to the closed end 39 of thedepending cylindrical member 40 formed integrally with said collar 33,and which adjacent its closed end is provided with an annular series ofoutlet openings 4|. A socket or cup-like member 42 is dimensioned toreceive the member 33 and is formed with a reduced externally threadedportion 43 having a bore 44, of slightly greater diameter than thecylindrical portion 40 extending therethrough, to provide the coil orlubricating space 45.

Seating in said socket member 42 is a thrust ball or roller bearing 43on which is supported collar member 38. The upper end of socket 42 isformed with, the threaded countersunk portion "in which is threadedlyengaged the packing ring 48, surrounding collar 38, and adapted to .atits lower end with a plurality of equi-spaced feet members 52 whichextend below the bottom element 33 and are adapted to be supported onthe bottom of the well. Base member 50 is provided with a central bore53 adapted to register with and form a continuation of bore 44 and oilspace 45. The bottom of said base member is threadedly countersunksurrounding the bore 53 met 54 to receive the'packing ring 55 mounted onthe lower end of the cylindrical portion 40 of member 38 for engagementwith packing 49, similar to ring 48. It will thus be noted that suchshoe construction effects a long bearing surface, extending from packingring 48 to the packing ring 55, for the reamer shaft 6 supported on thethrust bearings 43 and carrying the reamer struc ture. Also theconstruction of the shoe and base portion is such as not only to providea stable supporting structure. but to prevent its bogging down and atthe same time effect fluid circulation through the shoe structure to thebottom of the well and thereby maintain thewell at all times clear ofthe material reaching the bottom from the reaming operation.

It should be noted here that while the threaded reamer end 3'! of shaft3 and the complementally hardened oil and the" like, and in such caseswhere no great depth of stratum has to be removed, it will operate morequickly than the form heretofore described. In Fig. 17 there is shown adrill .pipe I, the upper collar 3*,shaft 3 sliding collar l3, and shoestructure C, which are similar to the parts 3, 3, l3, and C heretoforedescribed. However, in this instance each of the articulated or hingedarms A comprise an upper arm section 33 with its upper end suitablyhinged to lug Il and a similarlower section 31 with its lower endsuitably hinged as at 38 to the shaft 3", in the present instance.adjacent to shoe C, but'which may be at any desired point spacedtherefrom. These arms are connected by an intermediate arm section 59hingedly connected as at to arm 53, and as at 3| to arm 51, the arm 59at all times extending in parallelism with shaft 3' whether in folded oroverlying position with respect to said shaft or'in expanded position. I

It will be observed that in the present instance there are four sets ofthese arms A, corresponding to the sets A heretofore described, but foropposed sets. Each of the arms 59 centrally of their length are formedwith a pair of ears 32, between which are hinged the outward ends of theupper and lower brace rods 33 and 34, respectively. The upper end of rod33 is suitably and hingedly connected to a lug 35 suitably formed on orattached to'the end surface of collar l8, and the lower end of brace rod34 is hingedly connected by pin 33 to collar 31 suitably anchored orattached to shaft 3-. Suitably connected at their upper ends to collar3', and at their lower ends to collar l3, are the thrust rods 32 whichoperate similarly to rods 32 except they are also connected to collar I3and not only transmit force from collar 3 to collar l8, and outwardly toarms 59 through the braces 33 and 34 and shaft 3', during ,the reamingoperation, but effect synchronous movement of the collar l3 with respectment of collar 3* onshaft 3" effects moving thearms and braces intofolded and overlying relation with respect to shaft 6*, since arms 51and braces 34 are hingedly secured to, shaft 3*, and in such foldedposition this form of reamer assembly B is ready for insertion into orremoval from a well, the operation in this regard being similar toassembly B. The forward outer edges of these arms are formed withcutting edges similar to arms l4, or as desired. The cam mechanism 24 isalso applicable to this form.

Fig. 16'diagramatically illustrates a well D drilled in' ground 38 andwith the form illustrated in Figs. 1 and 2 in operative position inprocess of forming or reaming the chamber E. When the arms A of thereaming assembly B are in closed position as shown in Fig. i, it isevident that the apparatus can be inserted in the well D with the shoeassembly C resting on the bottom of the well, and when rotary movementhas been imdevice upwardly.

be below recesses 20, the upward movement of parted to the device,,chamber E will be formed. While the operation of the device would seemto be clear from the above description, it might be well to furtherstate that when the device is 'wardly on said shaft, and as the cams I!are positioned in cam recesses 20 the lower collar is prevented frommoving downwardly. Therefore, the arms A at joint I will move outwardlyin expanding direction and in reaming engagement with the wall of-thewell until they have substantially reached their expansive limit, asshown in'Fig. 4, and at which time the cams i3 have moved out of therecesses 20, so that as force is applied to collar 3, collar l3 and armsI are moved down in reaming direction, since force is applied directlyfrom collar 3 to arms I! and to collar l8 through thrust rods 32 saidcollar II and arms are free to move downwardly in reaming direction asshown in Fig. 16. At the same time the reaming structure is supported bythe shoe. structure C resting on the bottom of the well, and itsformation, including the cleats or feet 52 and bottom 39 tend to preventit from sinking into said bottom, thereby permitting the fluid streambeing pumped through said shaft 6 and the shoe structure to dischargethrough lateral openings 4! and to carry the reamed material that hasreached the bottom of the well upwardly between the shaft 6 and the wallof the well, and from chamber 5, out of the top of the well. This notonly maintains the well at all times clean, but the material content ofthe fluid is entrained with theupward flow as it passes through chamberE by the rotating action of the arms causing an outward motion of thecirculating fluid against the walls of the chamber by the whirlingmovement set up in the fluid which not only effects a continuous passageof the fluid from the well and insures the eiiicient removal of wastematerial, but lubricates and maintains the cutting portions of thereamer arms cool.

In initially starting the device, the arms l2 and I may not moveoutwardly by reason of being on dead center or otherwise, and toovercome this difliculty and to insure positive action and immediatebreaking of the joint irrespective of the position of the arms, a steelball 9 is inserted in the drill and fluid supply pipe above the cams 24,and the fluid passing through bore it forces the ball against the camsurfaces 22' which actuates the cams to open position permitting theball to pass through, and at the same time elevating arms 23 intoengagement with arms 13, thereby breaking the Joint and starting theoutward movement of the arms as shown in Fig. 5. Also, I might add, thatafter collar II has moved below recesses 2|, the folding of the arms Amay be effected at any point desired since cams ii are free to move intorecesses II.

To remove the device from the well, if the cams I! are not belowrecesses 23, upward movement of the drill pipe and collar 3'fold thearms into parallelism with the shaft, as in the first instance, and headI engaging shoulder 3, pulls the entire However, should the cams llcollar 3 will fold the arms, and-when cams II have reached the upperends of recesses 2|, being un-' able to pass beyond said ends, the shaftand connected parts will be moved upward as above described.

It is to be noted that theball I, after passing through cams 24, passeswith the fluid to the bottom of the shoe and rests on bottom 39 belowopenings 40 and, therefore, may be recovered for future use when theapparatus has been withdrawn from the well.

From the above description it will be apparent that I have designed anoil well reaming or cutting device which has for its principal purposethe reaming out to a larger diameter of such portions of oil wells aspass through oil bearing strata, in

order to increase the exposed surfaces of such strata and thus induce alarger flow of oil. The entire device is mounted on the reamershaft 3comprising the reamer assembly B including the upper collar 3, lowerslidable collar i3, the sets of expansible reamer arms A, and the shoeassembly C.- The construction of the arms and collar connections is suchthat while they have free foidable and expansible vertical movement theyare prevented from horizontal movement independently of the movement ofcollar 3. There is means carried by its upper end for preventing shaft0, slidable through said collar 3 and adapted to extend within the drillpipe I, from separation from said collar which is adapted for detachableconnection with drill pipe i. Said device is compact in form, and theweight of the parts below collar 3 automatically eflects folding of thearms with respect to the shaft during the lowering of the device intothe well and its withdrawal therefrom, said device being versatile inits adaptive use under varying operating conditions, and especially byreason of the arm assembly 13 being interchangeable with assembly Bwithout necessitating material structural alterations, said device beingsimple in construction, manufacturable at a reasonable cost, andefficient for the purposes intended.

Although in practice I have found that the form of the inventionillustrated in the accompanying drawings and referred to in .the abovedescription as the preferred embodiment, is the most efllcient andpractical, yet realizing the conditions concurrent with the adoption ofmy invention will necessarily vary, I desire to emphasize that variousminor changes in details of construction, proportion and arrangement ofparts, may be resorted to within the scope of the appended claimswithout departing from or sacrificing any of the principles of thisinvention.

Having thus described my invention, what I desire protected by LettersPatent is as set forth in the following claims:

1'. A well reaming apparatus comprising a rotary drive member, a reamershaft, a reaming assembly slidably mounted on and adapted to rotate withsaid shaft comprising upper and lower collars, an articulated cuttingarm hinged intermediate its length and having its ends atinto a seatformed in said shaft releasable when said arm has substantially reachedits predetermined expanded position, and means including a stationarymember for rotatably supporting the lower end of said shaft.

2. A reaming apparatus comprising a rotary drive member, a reamer shaft,a reaming assembly connected to said drive member and slidably mountedon and adapted to effect rotation of said shaft and comprising upper andlower collars, collapsible reaming arms having their ends attached,respectively, to the upper and lower collars, co-acting means betweenthe lower ends of the arms and shaft to prevent the downward movement ofsaid lower collar during the expanding movement of said arms butreleasable when said arms have substantially reached-their expandedpositions, said'means including cams on said arms normally seating inrecesses in'said shaft, and means including a stationary member forrotatably supporting the lower end'of said shaft.

- 3. A well reaming apparatus comprising a rotary fluid supply drillpipe, a hollow reamer shaft, 9, reaming assembly slidably mounted on andhaving rotary drive connection with said shaft and including upper andlower collars, articulated expansible arms operable by the up wardmovement of said upper collar intoparallellsm with said shaft and havingtheir ends attached, respectively, to the upper and lower collars, meansduring the downward movement of said upper collar for maintaining thelower collar fixed with respect to said shaft until the arms havesubstantially reached their expanded positions, said means includingcams on said arms normally seating in recesses in said shaft, meansincluding a stationary member for rotatably supporting the lower'end ofsaid shaft, said stationary member having a central bore forming acontinuation of the bore of said shaft whereby a fluid flow is directedthrough and below said device and stationary member to the bottom of thewell.

4. A well reaming apparatus comprising a rotary fluid supply drill pipe,a hollow reamer shaft in communication with said pipe, a reaming as-.sembly slidably mounted on and having rotary drive connection with saidshaft and including upper and lower collars, articulated cutting armshaving'expanded and collapsed positions attached to said collars, saidupper collar being attached to said drill pipe, means including astationary member for rotatably supporting the lower end of said shaft,said means having a central bore forming a continuation of the bore ofsaid shaft whereby a fluid flow is directed through said device andstationary member to the bottom of the drill pipe and a reamingmechanism operated by said dri-ll pipe, said mechanism including areamer shaft and a reaming arm assembly slidably mounted on saidshaft'comprising a plurality of articulated reaming arms and upper andlower reamer arm carrying collars, the upper collar being secured tosaid drill pipe, said arms by the upward movement of said upper collarbeing movable to and normally extending in closed substantialparallelism with said shaft but expansible to reaming position by thedownward movement of said upper collar, means for maintaining said lowercollar'against slidable movement until the arms have moved to expandedposition, said means including cams formed on said arms normally seatingin recesses in said shaft. means for limiting the meeting movement ofsaid collars and adapted to transmit force direct from the upper to thelower collar when force is applied to said upper collar in reamingdirection, and means for rotatably supporting the lower end of saidreamer shaft.

ii. A reaming apparatus comprising a rota y drive member, a hollowreamer shaft, a reaming arm assembly mounted on said shaft having con-'nection with saiddrive member and includini; an articulated reaming armnormally extending in overlying parallelism with said shaft and operableinto said position by said drive member and also-by said drive memberexpansible to reaming position, means for starting the initial outwardmovement of said arm in expanding direction extending within said shaft,and means rotatably supporting the lower end of said shaft.

7. A reaming apparatus comprising a rota y drive member, a bored reamershaft, a reaming arm assembly mounted on said shaft having connectionwith said drive member and including anarticulated reaming arm movableinto overlying parallelism with said shaft and expansible to reamingposition, by the upward and downward movement, respectively, of saiddrive member means in connection with said shaft and coacting with saidarm to eflect the initial outward movement of said arm in expandingdirection, said means including displaceable elements extending into thebore of said shaft and means operable through said bore for displacingsaid elements, and means rotatably supporting the lower end of saidshaft.

8. A reaming apparatus comprising a rotary drive member, a hollow reamershaft through which a fluid stream is adapted to flow, a reaming armassembly mounted on said shaft havin connection with'said' rotary drivemember and including reaming arms operable by the upward movement ofsaid member into overlying parallelism with said shaft and expansible toreaming position by the movement of said member in downward direction,displaceable means in connection with said shaft co-acting with saidarmsandmeans operable through the bore of the shaft for displacing saidmeans to effect starting of the initial outward movement of said arms inexpanding direction, and means rotatably supporting the lower end ofsaid shaft.

9. A reaming apparatus comprising a rotary driving member, a reamershaft, a reaming assembly slidably mounted on said shaft and rotatabletherewith including upper and lower collars, a plurality of reaming armsconnected to said upper collar and at their lower ends to said lowercollar, said arms comprising upper and lower hingedly connected reamingsections, said arms being operable into overlying parallelism withrespect to said shaft by the upward movement of said upper collar, butexpansible to open learning position by the downward movement of saidupper collar, cam means carried by the lower ends of the lower armsections co-acting with cut out seats formed in said shaft to maintainthe lower collar fixed but releasable to permit downward movement ofsaid coller when said arms have substantially reached their expandedposition, and means for rotatably supporting the lower end of saidshaft, said upper collar being connected to and operated by said rotarydriving member and means in connection with said shaft for initiatingand expanding movement of said reaming arms.

10. A reaming apparatus comprising a rotary driving member, a reamershaft, a reaming mechanisni connected to said rotary member and slidablymounted on said shaft and rotatable there- 11 a with including upper andlower collars connected by a plurality of expansible reamer arms, saidarms being operable by the upward movement of said upper collar intooverlying parallelism with respect to said shaft, but expansible toreamin position by the downward movement of said upper collar, cam meansassociated with said arms and adapted to seat in recesses formed in saidshaft to maintain the lower collar fixed during the expanding movementof said arms, said cam means being displaceable to permit movement ofsaid collar with respect to said shaft when said arms are in expandedposition, and additional recesses in said shaft adapted to co-act withsaid.

cams, when said lower collar has moved below said first mentionedrecesses, to permit collapsing of the arms at any desired point withrespect to said shaft, and means for rotatably supporting the lower endof the shaft. V

11. A reaming apparatus comprising a rotary driving member, a reamingshaft, a reaming mechanism mounted on said shaft and rotatabletherewith, comprising a pair of collars slidable on said shaft,including an articulated reamer arm associated with said shaft andattached to and controlled by the upper collar, said upper collarconnected to andcontrolled by said rotary member, said arm beingoperable into overlying parallelism with respect to said shaft andexpansible to open and reaming position by the upward and downwardmovement, respectively, of said upper collar, said arm comprising upper,lower, and intermediate hingedly connected sections, and means forrotatably supporting the lower end of said shaft.

12. A reaming apparatus comprising a rotary driving member, a reamershaft, a reaming mechanism mounted on said shaft and rotatable therewithincluding upper and lower slidable collars, rods interconnecting thecollars adapted to transmit force from the upper to the lower collar andto effect their synchronous movement, said v said upper collar andexpansible to open. position by the downward movement of said uppercollar. said upper collar being connected to and operated by said rotarydriving member, and means for rotatably supporting the lower end of saidshaft.

13. In combination with a rotary drill pipe, a bored reamer shaft, areaming arm assembly slidabiy mounted on said shaft and includingupperand lower collars, a plurality of reaming'arms attached to saidcollars, said arms being operable into overlying parallelism withrespect to said shaft by the upward movement of said upper collar andexpansible to open position by the downward movement of the uppercollar, means on said shaft eo'-acting with cams in connection with saidarms and normally seating in recesses in said shaft to maintain saidlower collar stationary during the expanding movement of said arms butreleasable to permit downward movement thereof when said arms havesubstantially reached their expanded position, additional recesses insaid shaft co-acting with said cams to permit folding of said arms atany desired point on said shaft, means carried by said shaft andco-acting with said arms operable to start the initial outward movementof the arms in expanding direction, and a shoe assembly comprising a'stationary base bearing member, a member attached to the lower end ofsaid shaft seating on said bearing member, rotatably supporting saidshaft and constituting a journal bearing projecting longitudinally fromsaid shaft through said base.

WILLIAM R. HARBOUR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,317,192 Jones Sept. 30, 19191,402,503, Krause Jan. 3, 1922 1,498,463 McCloskey et a1. June 17, 19241,544,757 Huflord et al July 7, 1925 2,290,502 Squires July 21, 1942FOREIGN PATENTS Number Country Date 331,945 Great Britain July 17, 1932

